This invention relates to a method of transmission, with the possibility of correcting error bursts, of information messages with k bits by means of code words with n bits forming s blocks of size d.sub.i, where i varies from 1 to s, s being the number of polynomials P.sub.i (X) resulting from the factorization of X.sup.n +1 over the field GF(2) with two elements and d.sub.i the degree of the polynomial P.sub.i (X).
The invention also relates to an encoding device and a decoding device for applying this method.
In transmission of information or data, there is often an increasing need for processes at least enabling transmission errors to be detected and , in most cases, attempts are made to correct these errors.
As regards the correction of one or several errors in the transmission, there are a great number of correction methods and a description of many types of code is given in the literature. However, attempts are being increasingly made to detect and also to correct bursts of errors, in order to improve the reliability of information transmission systems. Amongst the families of codes enabling satisfactory performances to be obtained, one of the most effective is that of the Bose-Chaudhuri-Hocquenghem (BCH) codes and, in particular, amongst these, the Reed-Solomon codes are amongst the most powerful and much research and application work has been carried out on them. The code words obtained can be considered as combinations of the elements of a Galois field GF(2.sup.m) and in order to process them, it is necessary to use specialized circuits consisting of complex arrangements of logic gates. In general, these circuits have an irregular diagram lay-out and call for a considerable number of special connections. Consequently, they are difficult to build in integrated circuit form. In addition, if it is intended to perform the necessary operations of multiplication of polynomials by means of read-only memories, these operations quickly become highly complicated and impracticable in integrated form as soon as the very lowest orders are exceeded.
Furthermore, correction of bursts of errors, even for BCH codes, requires a fairly considerable number of redundant bits.